arm64: exception handler registration

In order to build upon the arm64 exception handlers need
to be registered. This provides very basic support to
register a handler for a specific exception vector.

BUG=chrome-os-partner:30785
BRANCH=None
TEST=Built and booted into kernel.

Change-Id: If046f0736765a2efeb23201c1d2d1f7f7db47dd2
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: a82e5e8d5900ebef16abdb68701be6beeb9ca13a
Original-Change-Id: I0f68a48101ff48d582f5422871b9e7e5164357e4
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/218650
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/9088
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

2 files changed, 49 insertions, 0 deletions

diff --git a/src/arch/arm64/include/arch/transition.h b/src/arch/arm64/include/arch/transition.h
index e8ded5f2aa..9da6b36b87 100644
--- a/src/arch/arm64/include/arch/transition.h
+++ b/src/arch/arm64/include/arch/transition.h
@@ -42,6 +42,24 @@
 #define STACK_POP_BYTES	 16
 #define STACK_PUSH_BYTES -16
 
+#define EXC_VID_CUR_SP_EL0_SYNC		0
+#define EXC_VID_CUR_SP_EL0_IRQ		1
+#define EXC_VID_CUR_SP_EL0_FIRQ		2
+#define EXC_VID_CUR_SP_EL0_SERR		3
+#define EXC_VID_CUR_SP_ELX_SYNC		4
+#define EXC_VID_CUR_SP_ELX_IRQ		5
+#define EXC_VID_CUR_SP_ELX_FIQ		6
+#define EXC_VID_CUR_SP_ELX_SERR		7
+#define EXC_VID_LOW64_SYNC		8
+#define EXC_VID_LOW64_IRQ		9
+#define EXC_VID_LOW64_FIQ		10
+#define EXC_VID_LOW64_SERR		11
+#define EXC_VID_LOW32_SYNC		12
+#define EXC_VID_LOW32_IRQ		13
+#define EXC_VID_LOW32_FIQ		14
+#define EXC_VID_LOW32_SERR		15
+#define NUM_EXC_VIDS			16
+
 #ifndef __ASSEMBLY__
 
 #include <stdint.h>
diff --git a/src/arch/arm64/include/armv8/arch/exception.h b/src/arch/arm64/include/armv8/arch/exception.h
index 11ffcb61f6..49ea747700 100644
--- a/src/arch/arm64/include/armv8/arch/exception.h
+++ b/src/arch/arm64/include/armv8/arch/exception.h
@@ -30,8 +30,39 @@
 #ifndef _ARCH_EXCEPTION_H
 #define _ARCH_EXCEPTION_H
 
+#include <arch/transition.h>
+
 /* Initialize the exception handling on the current CPU. */
 void exception_hwinit(void);
 void exception_init(void);
 
+/*
+ * Order matters for handling return values. The larger the value the higher
+ * the precedence.
+ */
+enum {
+	EXC_RET_IGNORED,
+	EXC_RET_ABORT,
+	EXC_RET_HANDLED,
+	EXC_RET_HANDLED_DUMP_STATE,
+};
+
+struct exception_handler {
+	int (*handler)(struct exc_state *state, uint64_t vector_id);
+	struct exception_handler *next;
+};
+
+
+/*
+ * Register a handler provided with the associated vector id. Returns 0 on
+ * sucess, < 0 on error. Note that registration is not thread/interrupt safe.
+ */
+int exception_handler_register(uint64_t vid, struct exception_handler *h);
+
+/*
+ * Unregister a handler from the vector id. Return 0 on success, < 0 on error.
+ * Note that the unregistration is not thread/interrupt safe.
+ */
+int exception_handler_unregister(uint64_t vid, struct exception_handler *h);
+
 #endif